I know submitting multiple answers is not encouraged, but in case I think it is justifiable. As Antoinette remarks, there is indeed a significant difference between BUITENschools and BOVENschools. If, in the given context, 'bovenschools' refers to an organisational layer above the level of individual schools, I think the term 'meta school' may more appropriate than 'extra curricular' or 'extra curriculum'. Please see the references below.

http://www.indiana.edu/~rcapub/v22n2/p41.html
Conceived as a ** meta-school ** that at its very foundations will promote cross-disciplinary collaboration among scholars in the arts, sciences, and humanities, the proposed School of Informatics will provide a central, formalized venue that ties together the dozen or more IU academic units currently involved in the study of information science, technology, and the growing role of digital media and communication.

http://www.cra.org/Activities/snowbird/00/dunn-crawk2-2.pdf
Faculty
•90 “founding faculty” from existing units.
Reimburse those units for the teaching.
•10 New Media faculty.
• 6 FTE other Informatics faculty
• 80-100 faculty FTE to be hired
(between Bloomington and Indianapolis)
assuming legislative funding.
• joint appointments will support ** meta school
concept **.

http://www.informatics.indiana.edu/policies/informaticsvisio...
The IU School of Informatics is a “meta” school, tying together and focusing work that is relevant to information technology and spread among a number of existing disciplines

http://www.eslcafe.com/forums/job/viewtopic.php?p=52938
Q: Anyone heard of this school?
A: They have a pretty good reputation. This school has a program of academic cooperation with Faculty of Education KASETSART UNIVERSITY Kampangsaen Campus. Their Board of Directors is solid.

In http://www.ctl.vcu.edu/pdf/Everything About Meta.pdf the term META is an acronym, but I get the impression that it could also refer to a meta school concept:
Department of Special Education and Disability Policy
Virginia Commonwealth University
Official title: Metropolitan Educational Training Alliance Alternative Licensure Program for Special Education
What is it?
A Partnership between Virginia Commonwealth University and Chesterfield, Hanover, Henrico and Richmond City school divisions intended to help instructional assistants become special education teachers of children and youth in one of three areas of special education.